1. Field of the Invention
The present invention relates to a robot coordinated control method and system for coordinating operation of a plurality of robots.
2. Description of the Related Art
When each of a plurality of robot control devices controls one or more robots and the plurality of robots controlled by these plurality of robot control devices jointly perform one job, there may be a need to coordinate the operation of the plurality of robots. In this case, generally, one of the plurality of robots is made the master robot, while the other robots are made slave robots. Further, the plurality of robot control devices are connected to each other using the Ethernet® or other communication connecting means, the current position of the master robot is transmitted from the robot control device of the master robot to the robot control devices of the slave robots through the communication connecting means, and the slave robots are operated based on the transmitted position data of the master robot.
The robot control cycle is set so as to begin synchronized to an operation basic period signal generated at a constant period inside the robot control device. However, each robot control device independently generates an operation basic period signal, and therefore a deviation in the timing of generation can occur between the different robot control devices. This deviation in the timings of generation of the operation basic period signals is not a problem in cases when one robot control device controls a plurality of robots for coordinated operation. However, when using a plurality of robots controlled by different robot control devices, if trying to coordinate operation without consideration of this deviation of the timings of generation of the operation basic period signals, a problem will occur that the plurality of robots cannot be accurately operated coordinately. Further, for example Japanese Unexamined Patent Publication No. 2003-145462 discloses adjusting the time interval from when one robot control device receives an operation instruction from another robot control device to the actual operations of the robots to coordinate the operations of the robots.
However, the robot coordinated control system described in Japanese Unexamined Patent Publication No. 2003-145462 adjusts the time interval from when one robot control device receives an operation instruction from another robot control device to the actual operations of the robots by changing the minimum interruption period of the robot control devices, and therefore causes the problems of control becoming complicated.